He always gets so pissed when i mention his ex name

Hi guys:

Well here is the issue: My boyfriend always goes crazy when i mention his ex, or even her son or anything. He gets mad, curse me, and say he is tired of hearing me say stuff bout her. Well sometimes I'm curious, that's why i ask stuff, and when he acts so pissed off, just makes me think shit like he is still not over her after all this time.
Why would he get so pissed off and even dont answer stuff i ask bout her, if he is done with her and she means nothing for him?
Just weird and i wanted to share. Any comments, would help
Thanks:)

He doesn't want to talk about it so leave the poor guy alone before he starts wanting to go back with her. Assuming that he' not there already.

Sounds fishy to me. I don't see why he gets defensive. Unless he just dislikes her a whole lot, and is trying to forget that part of his life. Then I could understand.
I have the belief that if you and your ex split for a reason, you should remember that reason, and question what either of the individuals would get out of maintaining a friendship after the breakup.
I have found that most of the time there is no reason, unless there is an emotional connection someone doesn't want to throw away. If that is the case then there is a real issue. An issue that is more than likely going to hinder any future relationships.
Explain to your boyfriend you were curious, and you don't mean to offend him. As long as he doesn't maintain a friendship/contact with her, I really think that the conversations and questions about the ex should be dropped. You don't want to come off as the crazy one! Remember, guys' do gossip.

Thanks sensualtulip, if you have the time and read my first post you can get more details of the issue, then i guess you could make your mind better of what can be causing it.
Your advice helps a lot:)

Why the heck are you even feeling a need to want to talk about his ex and mention her for??

You only serve to fill his head with memories of HER and when you do that.